Ulota crispula Bridel
Plants to 2.5 cm. Stem leaves twisted-crisped when dry, narrowly-lanceolate to linear lanceolate, 1.7--3 mm; leaf base ovate, concave; margin plane to reflexed; distal laminal cells 7--10 µm wide, with conic papillae; basal laminal cells linear-elongate grading to quadrate at margin, thick-walled. Sexual condition autoicous. Seta 1--3 mm. Capsule short-oblong to oblong, 0.8--2 mm, strongly 8-ribbed from 3/4 to entire length; stomates numerous in neck and lower 1/3; peristome double; endostome segments 8, smooth; exostome teeth 8, reflexed, densely papillose below, lightly papillose-reticulate above. Calyptra conic, very hairy. Spores 23--29 µm.
Common on branches and trunks of trees, especially Betula species; low elevations; N.B., Nfld., N.S., Ont., PE.I., Que.; Conn., Del., Ga., Ill., Ky., Maine., Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio., Pa., R.I., S.C., Tenn., Ver., Va., W.Va., Wis.; Europe; Asia.
This species is distributed from Newfoundland west to Minnesota and south in the Appalachians to northern Georgia, and is not known west of the Mississippi River. The most common Ulota species, it is easily distinguished by crisped leaves (when dry), capsules contracted beneath the mouth, and a reflexed and well-developed peristome. Although variable in size, it is smaller than the western U. obtusiuscula and has shorter capsules. The former species also has flexuose, less reflexed, exostome teeth.